Cylinder ridge reamer



June 1935- H. w. ZIMMERMAN CYLINDER RIDGE REAMER Filed July 16, 1932 2 Sheets-Sheet 1 J1me 1935- H. w. ZIMMERMAN CYLINDER RIDGE REAMER Filed July 16, 1932 2 Sheets-Sheet 2 Patented June 11, 1935 2,004,141 CYLINDER RIDGE Herman W. Zimmerman, Chicago, IlL, assignor to Automotive Maintenance Machinery 00., Oil!- cago, 111., a corporation of Illinois Application July 16, 1932, Serial No. 622,918

9 Claims.

My invention relates generally to cylinder tools for truing up worn cylinders, and it has to do more particularly with a reaming tool well adapted for the removal of circumferential ridges formed by wear occasioned by movement of piston rings along the cylinder wall surface.

As is well known, piston rings tend to wear away the cylinder wall surface throughout their range of travel. Regardless of the type of motor, the upper limit of the ring travel is always below the top of the cylinder, wherefore the wear occasioned by the rings leaves a ridge surface around the top of the cylinder. This ridge varies in extent (as in the valve-in-head and L-head type motors) dependent upon the nearness of the upper limit of ring travel to the top of the cylinder. Also, the upper edge of the ring tends to wear on a bevel, and a complemental shape is therefore given to the cylinder wall surface at the juncture of the part thereof worn by the ring and the unwom ridge surface. Consequently, when a new and unworn, square edged ring is installed on an old piston, or even a new piston, the upper edge of the ring strikes the rounded surface at the base of the ridge and produces a sharp clicking sound. This same condition exists in a worn cylinder in case the main or connecting rod bearings are taken up thereby raising somewhat the upper limit of the ring travel. This action is not only objectionable from proper ring seal standpoints but produces increased and rapid wear of the rings causing them to break down and to cease to function properly much more quickly than otherwise. It is, therefore, quite desirable in the reconditioning of cylinders to remove the ringwear ridge and the principal object of my invention is to provide a simple, inexpensive and improved tool for this purpose.

Attempts have been made heretofore to provide a tool for cutting the ring-wear ridge, but such prior tools depend upon the ridge surface for guiding and supporting the tools in their dressing movements. Such prior tools must therefore have rotating supports which must necessarily have some clearance in the cylinder to permit of proper rotation. For these, among other, reasons, these prior tools have been found unsatisfactory. Carbon deposits and other foreign substance which may be deposited on the ridge surface and any irregularities in such surface make it practically impossible to cut away the ridge on a true and smooth circle. Chattering of the tool takes place with consequent rough cut surfaces which. for reasons well known, are highly obiectionable. It is, therefore, another object of my invention to provide a tool of the foregoing character which does not flnd its support upon the ridge surface but which is supported by the cylinder, approximately on center, and entirely independent of the ridge surface. More particularly, my invention contemplates a tool having an adjustable support frame or unit adapted to be firmly and non-rotatably engaged with the cylinder surface beneath the ridge, and another frame or unit supporting a cutting blade which is rotatable about and upon the support frame with the cutting blade in contact with the ridge surface; wherefore, the only part of the tool which engages the surface to 'be reamed or shaved is the cutting blade with the result that this surface may be out true and smooth and the cutting action will not be in any way affected by any irregularities in the surface to be cut.

Furthermore, for reasons well known, the cylinder, at the points of wear, tends to wear in an oblong shape, wear taking place to a greater extent on one side of the center line than on the other. This condition, when utilizing this ring-worn surface for supporting purposes, presents a problem in attempting to center or nearly center the tool in the cylinder; and a further object of my invention is to provide a form of supporting means which is adapted to approximately center the tool within the worn portion of the cylinder. To that end, I provide a. supporting section having three adjustable support members, one of which is adapted to be seated against the cylinder wall on the major axis of the oblong section of the cylinder.

It is well known that cylinders for various types of motors vary in shape, particularly at their upper portions for purposes of valve clearance, combustion chamber shape, et cetera. For example, the top of the cylinder wall may be formed with a bevel or chamfer of nonuniform depth or a part of the upper cylinder wall surface may be vertically and/or laterally offset so that the above-mentioned ridge which is formed due to wear caused by the piston rings will be of irregular shape and depth. Considerable difficulty is experienced in removal of such ridges with prior ridge removing tools which are supported within the ridged surface. It is, therefore, a further object of my invention to provide a tool adapted to easily and quickly remove ridges formed in the cylinder regardless of their shapes, and without requiring special skill on the part of the operator.

It will be further appreciated that, if the tool guiding and supporting means were associated directly with the cutting blade and with the surface to be reamed, the extent of out which would be permissible would be practically within the limits of the minor axis of the oblong cylinder section thereby leaving a slight and objectionable ridge portion at the major axis of the oblong section. On the other hand, it will be seen that if the reaming should be continued to the dimension of the major axis of the onlong cylinder wall section there will be a. tendency, particularly in badly worn cylinders, to provide a counter-cut ledge around the cylinder of the minor axis portion; wherefore, in the installation of new pistons and rings and/or new rings and/or adjustment of bearings the upper limit of ring travel may be such that the upper ring might catch on this ledge with consequent objectionable results. My invention eliminates this condition and provides a tool which is adapted to dress away the entire ridge surface so that it is completely eliminated so far as the entire worn cylinder wall surface is concerned. More particularly, my invention contemplates the use of a novel cutting blade arrangement which may be so related to the supporting structure that it will cut away the ridge on a taper providing a flaring surface above and joining with the worn cylinder wall therebeneath.

Other objects and advantages of my invention will become apparent as this description progresses and by reference to the drawings wherein,-

Figure 1 is an elevational view of one form of tool embodying my invention, the same being diagrammatically shown positioned in a worn cylinder ready to be dressed;

Fig. 2 is a section taken substantially on line 2-2 of Fig. 1;

Fig. 3 is a section taken substantially on line 3--3 of Fig. 1;

Fig. 4 is a vertical sectional view taken substantially on line 4-4 of Fig. 1;

Fig. 5 is a fragmentary view of the frame or unit which supports the cutting blade, a portion of the blade retaining structure being removed to better illustrate the shape of the blade and its relationship to its supporting structure;

Fig. 6 is a view similar to Fig. 5 except the ends of the cutting blade are reversed;

Fig. '7 is an enlarged fragmentary section through the lower frame or unit of the tool, more clearly illustrating the structure of the adjustable guide members which engage the cylinder wall surface for support of the tool; and

Fig. 8 is a section taken substantially on line 88 of Fig. 3.

It will be understood that, while I have shown my invention applied to a tool adapted particularly for the removal of cylinder ridges of the character hereinabove mentioned, it is not necessarily limited to this use but may find utility in any instance where similar problems and conditions of use are to be met.

Referring to the particular structure shown in the drawings, the tool is illustrated in connection with a cylinder l which has been worn in use, for example, as at H leaving an unworn ridge surface l2 at the top of the cylinder. This worn cylinder surface supports the tool independently of the tool cutting portion and the structure preferably employed for this purpose will now be described.

This support structure includes a cage-like frame or unit which, preferably; takes the form of top plate |3 to which a plurality of annularly spaced posts M are rigidly connected for guidingly centering and supporting a movable bottom plate I5. The posts I define three radial passageways in which there are disposed a corresponding number of guide-centering members or sections l6. These guide members l6 are supported by the top and bottom plates |3, If as follows: Plate 3 is provided with radial grooves extending from its outer periphery to its central portion and in which straight edged end or tongue portions I6 of the members l6 are adapted to seat for guidance and support. The bottom plate I is provided with a similar number of aligned grooves 8 which are provided with inwardly tapered base portions I8 upon which are seated oomplementally shaped edge portions l6 of the guide members It. The members l6 are expansible and contractible to engage the tool with and release it from the cylinder wall surface ll.

This is accomplished by movement of the bottom plate I5 toward and from the top plate 13 by virtue of the complementary taper-shaped groove and member surfaces l8, Hi. In other words, movement of the bottom plate l5 toward the plate I3 expands the members I6, and movement of this bottom plate in the opposite direction permits of contraction of the same by a spring ring I!) which passes around and over the members l6 and which is seated in suitable grooves |6 therein. This spring tends to, at all times, hold the member and plane surfaces I8 and I6 firmly engaged with each other. Movement of the bottom end plate is accomplished by means of an axially disposed stem 20 which has its lower end only threaded and engaged with a threaded opening in the bottom plate I 5. The upper portion of this stem is journaled in the top plate I3 and its extension 2|, all

of which will be described more fully hereinafter.

The top plate l3 rotatably carries a blade supporting frame or unit which will now be described. The end plate extension 2| rotatably and telescopically receives a tubular member 22 which is locked thereto against longitudinal dis placement. Specifically, the member 22 is provided at one side with an opening 23 which aligns with a groove 24 in end plate extension 2|. A ball 25 is seated in the groove 24 and is of sufficient diameter to extend also into the opening 23. The ball is held in place therein under tension by a spring 26 confined by a screw 21 screwed into the outer end of the opening 23. In this manner, the rotation of the blade supporting unit is tensioned to prevent too free movement thereof and to give a so-called feel" to the tool in operating the same to ream the cylinder ridge.

The tubular member 22 is extended upwardly, or outwardly, beyond the end plate extension 2| and is provided at its outer end with a cage head 28 which is adapted to receive an adjusting nut 29 and confine the same against longitudinal displacement while permitting rotation thereof.

This cage head, being open at its opposite sides,

lends access to the knurled periphery of the adjusting nut 29 in order that the same may be grasped by the hand of the operator androtated. The adjusting stem 20 is extended rotatably on through the top plate extension 2| and upwardly through the tubular member 22 and through a suitable opening in the adjusting nut 29 to which it is secured by a pin 30; wherefore, rotation of the .nut 29 causes rotation of the stem 20 and axial movement of the plate I5 and consequent adjustment of the guide members l6 for contraction or expansion of the tool dependent upon the direction of rotation of the nut 29. In order to prevent rotation of the nut 29 and the stem 2| from affecting the tension between the rotatable cutter section and the stationary support section, I secure a washer 3| to the adjusting stem 28 at the end of the end plate extension 2| so that such washer will ride upon the end of such extension. With this arrangement, it is obvious that any longitudinal or axial pull effected by rotation of the nut 29 will take place only as between the end of the end plate extension 2| and the bottom plate l5 and will not in any way affect the predetermined rotative relationship existing between the tubular member 22 and the end plate extension 2|.

Rotation of the cutting blade unit is accomplished, preferably, by hand but it is to be understood that suitable power means may be employed if desired. In the particular form of structure shown in the drawings, the outer end of the cage head 28 is provided with a threaded opening in which the threaded stem 32 of a rectangularly-shaped drive shank 32 is received. Any suitable tool, such as a wrench, may be employed to engage the shank 32 and rotate the cutting blade unit.

The reaming or cutting action is accomplished by a single blade device 33. Specifically, the lower part of the member 22 is extended laterally as at 34 and is provided with a horizontal, rectangularly-shaped groove 35 which snugly and slidably receives the similarly-shaped cutting blade 33. The outer surface of this slot is closed by a removable plate 36 which has its bottom edge seated and confined in a groove 31 formed in an extension 38 of the bottom side of the blade groove 35, and the upper end of this plate is detachably secured in place by a screw 39.

The cutting blade is mounted for adjustment toward and from the cylinder wall surface. Specifically, the opposite sides -of the cutting blade are provided with diagonal grooves 40, 4| extending in opposite directions from the central portion of the upper edge of the blade toward and near the opposite ends thereof. Expansion and contraction movements of the blade are accomplished by a vertical slide member 42 having a diagonally and complementally disposed feather 43 snugly and slidably engaging the groove 40 or 4| as the case may be. The arrangement is such (for example, in Fig. 5) that downward movement of the slide member 42 causes the feather 43 to approach more closely to the bottom of the slot 4| and consequently contract or draw in the then-operative cutting edge of the blade; and movement of the member 42 in an opposite direction results in expansion of the cutting blade by the opposite movement of the feather 43 in the groove 4|.

The slide member 42, preferably, takes the form of a rectangular strip and it is supported partly in a slideway 44 formed in the back wall of the blade-carrying groove 35 and partly in a rectangularly-shaped opening 45 extending upwardly in the extension 34. The bottom groove wall and its extension 38 are also-provided with an aligned opening 46 which receives the lower end of the member 42. range of adjustment of the slide member 42 is such that the feather 43 may be projected down through the bottom opening 46 or up into the upper opening 45 when moving such member into its extreme opposite positions. The slide member 42 is held against outward displacement from its supporting groove 44 and with respect to the openings 45 and 46 by an enlarged, offset and rectangularly-shaped head portion 42 on the upper end of such member, which head fits snugly and slidably within the upper opening 45. To this head there is connected an upwardly projecting threaded stem 41 which passes freely through and beyond the top of the extension 34 for engagement with a threaded adjusting nut 48 normally confined rotatably between the bottom of the cage head 28 and the top of the extension 34. With this arrangement, it will be obvious that upon rotation of the nut 48 in a clockwise direction, the slide member 42 and its feather 43 are raised and the cutting blade expanded, and vice versa when the nut is rotated in the opposite direction. The slide member 42 is limited in its downward adjusting movement by the lower edge thereof passing through the opening 46 and striking the upper surface of the top end plate l3, and adjustment of this member in the opposite direction is determined by the threaded end of the stem 41 striking the bottom surface of the cage head 28. a

As hereinabove explained, in the case of badly worn cylinders, and due to the oblong shape to which the cylinder is worn, it is necessary to guard against the forming of any under-cut ledges on which the rings would tend to catch under certain conditions of operation. My invention contemplates a bevel out under such circumstances which permits of complete trimming down of the cylinder ridge flush with the worn cylinder surfaces. Specifically, the cutting edge A of the knife 33 is straight and may be suitable for trimming ridge surfaces where the cylinder is only slightly worn. The other edge B of the blade is tapered inwardly to a slight degree from top to bottom so that when the cutter carrying frame is rotated with this edge in contact with the cylinder wall ridge a corresponding bevel cut will result, the depth of the bevel, of course, varying with the extent of uneven wear in oblong shape. The reversibility of the blade is obvious by reference to Fig. 6, the adjustment grooves 40 and 4| being reversible, as illustrated, for proper adjustment of the blade in either position thereunder.

It will also be seen in Fig. 3 that blade 33 is so mounted that it is located forwardly, with respect to direction of rotation of the tool, of the tool axis. The end of the blade is squared, and the blade is so inclined with respect to the cylinder wall that the forward edge of its end serves as the cutting edge, and this cutting edge trails the blade body so as to cut the cylinder surface with a drag-cut or scraping action. This eliminates chatter and digging-in tendencies in the cutting action and insures a clean smooth out.

The mode of operation of my invention will be obvious from the foregoing. Briefly, the tool is mounted in the cylinder with its supporting section beneath the cylinder ridge I2 and with the guide-support members I 6 seated against the worn surface ll'. One of the guide members It is positioned, preferably, on center with the major axis of the worn oblong'section. of the cylinder. lWith the parts in this position, the adjusting nut 29 is actuated to seat the members It firmly against the cylinder wall surface so that the tool is locked and self-supported therein. The cutting blade 33 is then adjusted to engagement with the cylinder ridge surface I2 and a suitable tool applied to the drive shank 32 for rotation of the cutter-carrying frame and resultant shaving of metal by the cutter edge. Adjustment of the blade 33 may be made from time to time until the ridge is removed.

While I have shown only one form of structure embodying my invention, it will be understood that other changes in details and arrangements of parts may be made without departing from the spirit and scope of my invention as defined by the claims which follow.

I claim:

1. A unitary tool of the class described which comprises a size-adjustable frame section adapted to immovably engage the cylinder wall inwardly of and independently of the surface to be treated and to thereby stationarily support the tool as a whole, another section rotatably supported by and above said frame section, means, including an externally accessible part, extend: ing through said sections for adjusting said frame section to desired size means preventing relative axial movement between said two sections, a cutting blade supported by said second section at an angle to the radius of said section and having its rearward end with respect to the direction of rotation provided with a square cutting edge adapted to contact-the cylinder wall whereby said cutting edge engages the cylinder wall with a drag-cut or scraping action, and means for adjustably moving said blade endwise toward and from the cylinder wall.

2. A tool adapted for removal of ridges formed.

on cylinder wall surfaces by ring wear which comprises a frame member, a plurality of radially adjustable elements carried by said frame member and firmly and immovably engageable only with the cylinder wall surface beneath the ridge to be reamed, another frame member rotatably supported by said first frame member, means preventing relative axial movement between said frame members, said means also retarding relative rotational movement between said frame members, a cutting blade adjustably carried by said second frame member at a substantial angle to the radius thereof, having its face at an acute angle to the cylinder wall and engageable in drag-cut fashion with the ridge to be dressed, means for adjusting said blade toward and from the ridge, and independent means, including a constantly accessible device carried by both of" said frame members for expanding and contracting said adjustable elements.

3. In a tool of the class described, a frame unit, a plurality of support elements carried by said frame unit, means for expanding said support elements to firmly engage the cylinder wall and to hold said frame unit against rotation therein, an extension on said frame unit, a cutting unit having a tubular member telescopically engaged with and freely rotatable upon said extension, a spring-pressed ball carried by one of said units and engaging a groove in the other for preventing relative axial displacement between said cutting unit and extension, a cutting blade adjustably supported by said cutting unit and having a straight cutting edge, means for adjusting said blade towardand from the cylinder wall, an accessible adjusting member rotatably supported against axial displacement by said cutting unit, and a connection between said adjusting member and said expanding means passing through said extension and cutting unit for adjusting said element expanding means without disturbing the other parts of the tool. I

4. In a tool of the class described, a pair of end plates one of whichvis movable toward and from the 'other, a pluralityof adjustable support members carried by said end plates, a stem having screw threaded engagement with said movable end plate for adjusting it toward and from the other end plate to adjust said support members toward and from the cylinder wall surface, 1

an extension on the non-movable end plate and in which said stem is rotatably supported, a blade-carrying unit rotatably journaled upon .said extension, a cutting blade carried by said unit at a point axially removed from said support members and to one side of the tool axis with its cutting edge trailing, means carried by said unit for adjusting said cutting blade toward and from the cylinder wall surface, and an exteriorly accessible means also carried by said unit for rotating said stem.

5. In a tool of the class described, a support unit having a plurality of adjustable sections adapted to engage the cylinder wall surface and hold said unit firmly in the cylinder against rotation, a blade-carrying unit, means for mounting said blade-carrying unit rotatably upon said support unit, a cutting blade supported by said blade-carrying unit at a point above said support unit, means for adjusting said blade, means passing through both said units for adjusting the sections of said support unit without affecting the rotatable connection between said two .units and without detachment of any parts, means holding said units against relative axial displacement during the relative rotation thereof, said sections adjusting means having a part accessible through the walls of the blade carrying means for adjusting said sections, and rotational drive connecting means on said blade carrying unit above said part.

6. In a portable device for removing the ridge of a worn cylinder, in combination: a support unit insertable into the cylinder including a plurality of radially movable parts, means for adjusting said parts into engagement with the cylinder wall to fix said unit in said cylinder and a bearing on the upper portion of said unit; a member operatively connected to said adjusting means and extending through and above said bearing, said member being provided with actuating means adjacent its upper end; a cutter unit comprising a body journalled on said bearing and extending above and substantially enclosing the extending portion of said member, said body being formed with a lateral opening to give access to said actuating means whereby the support unit may be fixed in the cylinder with said units assembled; a radially adjustable cutting blade carried by the cutting unit; and a spring pressed ball member carried by said cutting unit and projecting into an annular groove in said bearing whereby said units are releasably held against axial separation and relative rotation therebetween is frictionally retarded.

'7. In a portable device for removing the ridge unit insertable into the cylinder including a plurality of radially movable parts, means for adjusting said parts into engagement with the cylinder wall to fix said unit in said cylinder and a bearing on the upper portion of said unit; a member operatively connected to said adjusting means and extending through and above said bearing, said member being provided with actuating means adjacent is upper end; a cutter unit comprising a body journalled on said bearing and extending above and substantially enclosing the extending portion of said member, said body being formed with a lateral opening to give access to said actuating means whereby the support unit may be fixed in the cylinder with said units assembled; a radially adjustable cutting blade carried by the cutting unit; and a friction element carried by said cutting unit and engaging said bearing for frictionally retarding relative rotation between said units to facilitate positioning said support unit in said cylinder.

8. In a portable device for removing the ridge of a worn cylinder, in combination: a support unit insertable into the cylinder including a plurality of radially movable parts, means for adjusting said parts into engagement with the cylinder wall to fix said unit in said cylinder and a bearing on the upper portion of said unit; a member operatively connected to said adjusting means and extending through and above said bearing, said member being provided with actuating means adjacent its upper end; a cutter unit comprising a body journalled on said bearing and extending above and substantially enclosing the extending portion of said member, said body being formed with an opening to give access to said actuating means whereby the support unit may be fixed in the cylinder with said units assembled; a radially adjustable cutting blade carried by the cutting unit; and a friction element carried by said cutting unit and engaging said bearing for frictionally retarding relative rotation between said units to facilitate positioning said support unit in said cylinder.

9. In a portable device for removing the ridge of a worn cylinder, in combination: a support unit insertable into the cylinder comprising a plurality of radially movable parts, and means for adjusting said parts into engagement with the cylinder wall to fix said unit in said cylinder; a member operatively connected to said adjusting means and extending above said unit, said member being provided with actuating means adjacent its upper end; a cutter unit comprising a body rotatably mounted with respect to said support unit and substantially enclosing said member, said body being formed with an opening to give access to said actuating means, whereby the support unit may be fixed in said cylinder with said units assembled; and a spring pressed friction element carried by one of said units and engaging the other for frictionally retarding relative rotation between said units to facilitate positioning said support unit in said cylinder.

HERMAN W. ZIMIVIERMAN. 

